System for analyzing moisture content of materials such as cotton

Abstract

A system for analyzing the moisture content of bulk cotton or other non-homogeneous flowable solid substrates comprising: an electrical sensor consisting of multiple electrically independent measuring electrodes, each of which independently measures the moisture content of different portions of the sample; a means of pressing the mass against the surface of the sensor to form a face of uniform substrate density on that part of the mass which is pressed against the sensor; means for analyzing such face for moisture content; and a means for releasing the pressure on the halted mass to allow it to resume movement.

We claim: 
     
       1. A resistivity based moisture measuring means for non-homogeneous materials comprising: (a) a plurality of electrically independent electrode pairs, wherein one electrode of each of the electrode pairs is electrically common, resulting in a plurality of electrically independent measurement electrodes with an electrically common reference electrode for all of the measurement electrodes, and possessing non-entraining contact surfaces; and   (b) signal processing means to independently review each electrode-based resistance measurement, culling those measurements which fall outside predetermined parameters, weighting, integrating and mathematically combining the signals of the remaining measurements, determining the resultant moisture content from the arithmetic mean of said remaining measurements and displaying the result.   
     
     
       2. The means of claim 1 further comprising a material temperature sensor which sends a signal used by said signal processing means in determining said resultant moisture content. 
     
     
       3. The means of claim 1 further comprising a pressure sensor for determining when adequate pressure is being applied by said non-homgeneous material to the surface of the measurement device for a valid reading. 
     
     
       4. The means of claim 1 wherein said signal processing means comprises a resistance-capacitance circuit and high impedance operational amp to convert resistance to a time pulse, a microprocessor based computer and software to measure time and convert the time pulse from each electrode channel to each channel's moisture, a microprocessor based computer and software to cull the unwanted readings, a microprocessor based computer and software to compute the resultant moisture content using the individual readings from the separate channels, and a microprocessor based computer to use the resulting moisture content in control, display the resulting moisture content, or communicate it with other controllers or computers. 
     
     
       5. The means of claim 1 comprising from about 3 to about 20 electrically independent measuring electrodes. 
     
     
       6. The means of claim 5 comprising from about 5 to about 9 electrically independent measuring electrodes. 
     
     
       7. The means of claim 1 wherein the time during which the product is pressed against the electrodes and the resistance measurement made ranges from about 0.1 to about 5 seconds. 
     
     
       8. The means of claim 7 wherein the time during which the product is pressed against the electrodes and the resistance measurement made is about 1 second. 
     
     
       9. The means of claim 1 wherein the material to be measured is an agricultural product. 
     
     
       10. The means of claim 1 wherein the material to be measured is cotton. 
     
     
       11. A method for analyzing the moisture content of flowable non-homogeneous solids comprising: (a) collecting multiple substantially simultaneous resistance measurements from a plurality of electrically independent measuring electrodes;   (b) independently calculating from each electrode-based resistance measurement a moisture content measurement and culling those measurements which fall outside predetermined parameters; and   (c) determining the moisture content of said solid by weighting, integrating and mathematically combining the remaining measurements.   
     
     
       12. The method of claim 11 further comprising taking a temperature measurement of said solid at the time of collecting said resistance measurements and using such to adjust said resistance measurements for temperature effects prior to determining the moisture content of said solid. 
     
     
       13. The method of claim 11 further comprising taking a pressure measurement of said solid to determine the appropriate time for collection of said resistance measurements. 
     
     
       14. The method of claim 11 wherein the material to be measured is cotton. 
     
     
       15. The method of claim 11 wherein the time during which the product is pressed against the electrodes and the resistance measurement made ranges from about 0.1 to about 5 seconds. 
     
     
       16. The method of claim 11 wherein the time during which the product is pressed against the electrodes and the resistance measurement made is about 1 second. 
     
     
       17. The method of claim 11 comprising collecting resistance measurements from about 3 to about 20 electrically independent measuring electrodes. 
     
     
       18. The method of claim 17 comprising collecting resistance measurements from about 5 to about 9 electrically independent measuring electrodes. 
     
     
       19. The method of claim 11 wherein said flowable solids are placed in contact with the sensor manually or robotically.